Effect of NQO1 C609T polymorphism on prostate cancer risk: a meta-analysis

BACKGROUND Some studies have found that the NAD(P)H quinone oxidoreductase 1 (NQO1) SNP609 is associated with an increased risk for several malignancies. Numerous epidemiological studies have evaluated the association between the NQO1 C609T polymorphism and the risk of prostate cancer. However, the results of these studies have been conflicting. The aim of this study was to provide a more precise estimation of its relationship with prostate cancer using a meta-analysis. METHODS Electronic searches of several databases were conducted for all publications on the association between the NQO1 C609T polymorphism and prostate cancer before May 2013. The odds ratio (OR) and its 95% confidence interval (CI) were used for statistical analysis. RESULTS A total of six studies with 717 cases and 1,794 controls were included. No significant association was found between the NQO1 C609T polymorphism and prostate cancer risk in the total population analysis. In subgroup meta-analysis by ethnicity, a positive association was found in an Asian subgroup (T versus C, OR 1.337, 95% CI 1.014-1.763, P=0.040; TT + CT versus CC, OR 1.419, 95% CI 1.053-1.913, P=0.021). However, no significant association in any genetic models was observed in Caucasians. CONCLUSION This meta-analysis showed that the NQO1 SNP609 T allele might be a risk factor for prostate cancer in Asians. However, this result should be verified by additional population-based studies with large sample sizes.